The vetibulo-ocular refle (VOR) reduces motion of images on the retina by evoking eye movements in the opposite direction from head movement. Motor learning calibrates the VOR gradually correcting the reflex whenever image motion is persistently associate with heat turns. In addition, motor learning in the VOR in the VOR depends critically on the function of the cerebellum, and the principles uncovered in studies of the VOR may apply generally to many motor systems that are thought to rely on cerebellum- dependent learning to maintain normal sensory-motor function and for recovery of function following brain damage. The investigator proposes to develop a model system that would take advantage of the genetic tools as well the pharmacological and surgical manipulations available in the mouse to study motor learning in the VOR. Gene knockout mice will be used to more directly link cellular pathways to cerebellar physiology and physiology to motor learning in the VOR. This application aims to perform the necessary preliminary description of the basic behavior and physiology of the VOR in normal mice and to begin to use some interesting cerebellar mutants that are available to analyze the neural mechanisms for the induction of learning.